高功率高可靠性9XX nm激光二极管

为了提高半导体激光二极管的输出功率和可靠性,通过在有源区两侧势垒层和波导层之间引入高禁带宽度的GaAsP,抑制有源区载流子的泄漏,极大地改善了器件的性能。研究结果表明:在10~40℃温度范围内器件特征温度从原来的150 K提高至197.37 K(-75.76℃),峰值波长随温度的漂移系数为0.207 nm/℃;条宽200μm、腔长2000μm的9XX nm激光二极管可靠性工作的最大输出功率高达14.4 W;器件在注入电流为7 A时取得71.8%的最大电光转换效率,斜率效率为1.21 W/A。器件在恒定电流下的加速老化测试显示激光二极管可靠性工作寿命达2000 h以上。     

半导体激光器光纤耦合输出光斑均匀性的研究

自行设计实验,采用CCD采集光纤末端输出的光斑,利用Matlab编写程序,分析了光纤输出光斑的光密度分布规律,并利用三维立体图进行直观表示.研究了光纤尺寸、数值孔径和弯曲程度对输出光斑均匀性的影响,结果显示,光纤越长,输出光斑越均匀;芯径与所用光源的尺度越接近,输出光斑越均匀;光纤弯曲后,光斑变得模糊化、均匀化,但光强变弱.     

半导体激光器边缘绝热封装改善慢轴光束质量

为了削弱激光器工作时芯片横向温度不均而导致的热透镜效应对慢轴发散角的影响,提高慢轴的光束质量,引入了边缘绝热封装方式,即在激光器芯片两侧与过渡热沉之间加入空气隙,以降低两侧的传导散热。利用有限元分析软件ANSYS 18.0对该封装结构中激光器芯片的温度进行仿真。结果表明:当工作电流为1.6 A,芯片与热沉的接触宽为200μm时,慢轴发散角由普通封装时的11.5°减小至8.2°,降幅为28%,光束参数积和光束质量因子也分别降低了28%和24%,热阻增大了6%。边缘绝热封装对器件激射波长、阈值电流、电光转换效率的影响很小。     

碳化硅封装高功率半导体激光器散热性能研究

为研究基于碳化硅(SiC)陶瓷封装的高功率半导体激光器的散热性能,将其与常用的氮化铝(AlN)陶瓷进行对比,使用基于结构函数法的热阻仪分别测量SiC和AlN封装F-mount器件的热阻值,得到SiC器件的总热阻约为3.0℃·W~(-1),AlN的约为3.4℃·W~(-1),SiC器件的实测热阻值比AlN器件低14.7%,实验结果表明SiC过渡热沉具有较好的散热性能。实验进一步测试了两种过渡热沉封装器件的输出性能,在16A连续电流注入时,915nm波段的SiC器件单管输出功率为15.9 W,AlN为15 W,测试结果显示SiC封装的器件具有更高的功率输出水平。     

975nm分布反馈激光器一级光栅的制备

优化设计了975 nm分布反馈激光器的一级布拉格光栅结构.将纳米压印技术与干法刻蚀工艺相结合制备周期为148 nm的光栅结构,通过优化调整刻蚀气体流量比、腔室压强和偏压功率等参数,得到了合适的光栅刻蚀工艺参数.扫描电子显微镜测试显示,光栅周期为148 nm,占空比接近50％,深度合适,表面形貌、连续性和均匀性良好.将所制备光栅应用于975 nm分布反馈激光器中,激光器输出性能良好,波长随温度漂移系数小,光栅对波长的锁定效果良好.     

Finite element analysis of expansion-matched submounts for high-power laser diodes packaging

In order to improve the output power and increase the lifetime of laser diodes, expansion-matched submounts were investigated by finite element analysis. The submount was designed as sandwiched structure. By varying the vertical structure and material of the middle layer, the thermal expansion behavior on the mounting surface was simulated to obtain the expansion-matched design. In addition, the thermal performance of laser diodes packaged by different submounts was compared. The numerical results showed that, changing the thickness ratio of surface copper to middle layer will lead the stress and junction temperature to the opposite direction. Thus compromise needs to be made in the design of the vertical structure. In addition, the silicon carbide (SiC) is the most promising material candidate for the middle layer among the materials discussed in this paper. The simulated results were aimed at providing guidance for the optimal design of sandwich-structure submounts.     

High power single mode 980 nm AIGalnAs/AIGaAs quantum well lasers with a very low threshold current

To achieve low threshold current as well as high single mode output power, a graded index separate confinement heterostructure （GRIN-SCH） A1GaInAs/A1GaAs quantum well laser with an optimized ridge wave- guide was fabricated. The threshold current was reduced to 8 mA. An output power of 76 mW was achieved at 100 mA current at room temperature, with a slope efficiency of 0.83 W/A and a horizon divergent angle of 6.3°. The maximum single mode output power of the device reached as high as 450 mW.     

新型高效冷却热沉设计及其流体热力学模拟

为了满足高功率密度的激光二极管列阵叠层的封装需求,设计了新型小通道高效冷却热沉,并利用Ansys-Fluent软件模拟了它的热特性和冷却水的流动特性。相对于传统的宏通道热沉,小通道热沉的有效散热面积的增加大大提高了其散热效果。同样的散热需求下,小通道热沉所需冷却水水流流速更低,因此也就降低了对水冷机的水压要求。对于不同散热要求的高功率密度激光二极管叠层封装的热沉设计,可根据本文所述的流体热力学模拟方法及其详细的数据分析,对该类小通道热沉进行结构参数优化、热特性仿真及所需冷却水流速的预估。所设计的高效冷却小通道热沉结构具有加工简单,成本低,且方便耐用、寿命长等优点,是高功率密度激光二极管叠层器件封装的有效散热热沉结构。